Control of stepping motors has involved various design configurations of the motor windings; extensive switching circuits; and the use of sophisticated circuit control elements. As the applications of stepper motors increases, the need for higher stepping resolution also increases.
One method to achieve a higher stepping resolution is by the use of a mechanical gear reduction unit between the motor and the output device. The motor itself is stepped in large angular increments and the output of the motor is applied to a gear reduction unit that converts the large angular motor rotations into smaller angular rotations of the output device. The potential disadvantage in this type of reduction is that the gears may jam, break or malfunction and the control is then lost or compromised.